I don’t agree with the Gemological Institute of America’s (GIA) grading system for colored gems. I don’t believe in creating “types” of gemstone categories and adjusting the grading scale to fit what is most common or what some trade groups want to sell in those categories. Flawless gemstones can and do occur in any material and type and should be graded as flawless. Likewise, a flaw is a flaw and should be graded as such regardless of the type of gem.

I’m sharing here what I believe is a common sense gemstone grading system for color, clarity, and treatments. Anyone who wishes can use this approach.

I don’t use the GIA’s grading system for colored stones, except when dealing with gemstones that I have had GIA certified.

Common Sense Gemstone Grading: Color

Color is an arbitrary thing. Different people as well as cultures have different tastes. A fair amount of variance is to be expected. In my opinion, once the clarity of a stone is graded correctly, people can decide what color(s) they prefer and make their choices accordingly. Yes, some colors are often considered more valuable than others. In general, the more intense and bright the color, the more valuable the gem. However, I feel the best way to account for color ranges is in the pricing, not grading, precisely because tastes and color perceptions vary widely.

Common Sense Gemstone Grading: Clarity

VVS1 (Very, Very Small Inclusion): Very small inclusion(s) under 10x loupe magnification, difficult to find.

VVS2 (Very, Very Small Inclusions): A few, very small inclusions under 10x loupe magnification, difficult to find.

VS1 (Very Small Inclusions): Very few small inclusions recognizable by an expert under 10x loupe magnification.

VS2 (Very Small Inclusions): Some small inclusions recognizable by an expert under 10x loupe magnification.

SI (Small Inclusions): Several small inclusions easily recognizable under 10x loupe magnification but don’t diminish the brilliance appreciably. (This is what I would call “eye clean,” but this term is often abused).

Common Sense Gemstone Grading: Disclosing Treatments

None Known: No known treatments. (Please note that there could be a very small possibility of some treatment done at the mine or before the cutter acquired the rough/stone that the cutter may be unaware of. However, in general, there will be no treatments of any kind in this grade category).

Unknown, but likely Heated: No known treatments, but an acknowledgement that this type of rough/stone is often heated.

Heat: Heat only. Heating is commonly done to lighten or eliminate an unwanted color in some rough/cut stones.

Unknown, but likely Treated: No known treatments, but an acknowledgement that this type of rough/stone is often treated.

Treatment(s): Treatment(s) are a fairly common practice and there are many types. Whatever treatment is detected in the specimen will be listed and defined.

Irradiated: Irradiation is used to change or improve the color of a cut/rough stone.

Unknown: If you have no idea if the specimen examined has been treated.